Hormone receptor signaling is critical for normal and tumorigenic growth in ovary, breast, and prostate. Recent studies from our lab and others have shown that known oncogenes, such as c-myc and ErbB2, are involved in androgen receptor signaling in prostate cancer. However, the connectivity between the specific pathways is still poorly defined. The experiments in this research proposal will provide important insight into these interactions through the combined study of conditional mouse models and in vitro cell culture. Specifically, they will determine whether downstream oncogenic effectors can compensate for androgenic signaling in vivo, answer if the androgen receptor itself can act as an oncogene, and elucidate how the androgen receptor regulates its downstream targets to control cellular growth. A clear understanding of the crosstalk between hormone receptors and oncogenic signaling pathways is essential for tumor biology as well as the development of targeted molecular therapies.